View the book

Read Online
(90.4 K)PDF
(16.9 K)EPUB
Kindle
Daisy
(2.8 K)Full Text
(47.9 K)DjVu

All Files: HTTPS

Resources

Bookmark

Creep/Rupture Behavior of Melt-Infiltrated SiC/SiC Composites Being Investigated (March 1, 2001)

Author: Hurst, Janet B
Subject: ELECTRON EMISSION; ELASTIC SCATTERING; SECONDARY EMISSION; ELECTRON BEAMS; ANGULAR DISTRIBUTION; BACKSCATTERING; FORWARD SCATTERING; ACCUMULATORS
Year: 2001
Language: English
Book contributor: NASA
Collection: nasa_techdocs

Description

The failure behavior of melt-infiltrated SiC/SiC ceramic matrix composites is under investigation at the NASA Glenn Research Center as part of NASA's Ultra-Efficient Engine Technology Program. This material was originally developed under the High Speed Research Office's Enabling Propulsion Materials Program. Creep and rupture data provide accelerated testing information to predict material behavior under engine use situations (1500 to 2400 F). This information gives insights into various material development paths to improve composites as well as improve understanding of failure mechanisms. The left figure shows the fracture surface of a CMC material following over 200 hr of testing at 2400 F. This surface demonstrates the kind of fibrous pullout desirable for maximum crack deflection, hence non-brittle failure. Microscopy suggests that creep and rupture of these materials can best be considered as a probabilistic property, rather than a material property. Fiber failure occurs first in isolated regions, while stronger adjacent fibers remain intact. The right figure shows a region where oxide deposits blur and round the fiber images. Because the oxidation kinetics of SiC are well understood, this oxide scale can be used as a measure of the length of time various regions of the composites have been exposed to the environment, hence providing vital information regarding the sequence of failure. The oxide scale in the right figure indicates an early failure of this tow of fibers, whereas adjacent tows remain oxide free, suggesting failure much later in time. The path of various cracks can be followed throughout the composite in this manner, suggesting failure mechanisms.

Creative Commons license: Public Domain

Be the first to write a review
Downloaded 54 times Reviews

Selected metadata

Identifier:	nasa_techdoc_20050196561
Document-source:	CASI
Documentid:	20050196561
Nasa-center:	Glenn Research Center
Online-source:	http://wayback.archive-it.org/1792/20100127000208/http://hdl.handle.net/2060/20050196561
Original-nasa-rights:	Unclassified; No Copyright; Unlimited; Publicly available;
Updated-added-to-ntrs:	2008-06-02
Licenseurl:	http://creativecommons.org/licenses/publicdomain/
Mediatype:	texts
Rights:	Public Domain
Identifier-access:	http://www.archive.org/details/nasa_techdoc_20050196561
Identifier-ark:	ark:/13960/t01z5388b
Ppi:	300
Ocr:	ABBYY FineReader 8.0